1. Field of the Invention
The present invention relates to a culture dish that is stackable and includes features that enable a user to easily handle the dish.
2. Description of the Related Art
Culture dishes are known and widely used in laboratory environments for growing cell cultures, bacteria, viruses and the like. In the cell growth application, cell cultures are grown from tissue cell samples that are placed in the dish and covered with a liquid medium that promotes cell growth when the dish is placed in a controlled environment such as an incubator. For this application, the culture dish is typically sterilized and treated to promote the binding of cells to the dish surface. The grown cells can be removed from the dish to facilitate examination, or the user can examine the cells while in the dish, using an instrument such as a microscope. In another conventional application, tissue cells are grown in a semisolid (rather than liquid) medium that does not bind to the dish. Thus, the medium can be readily removed to recover the cells by simply turning over the dish.
A further conventional application for culture dishes is in the molecular biology field in which cultures such as bacteria and the like can be grown in or on an agar-based medium within the dish. Plaque lifts of the cultures grown on the medium are taken for examination by laying a membrane over the medium and on the cultures, and then lifting the membrane from the medium.
To control evaporation of the medium and prevent contamination of the cultures, culture dishes generally include a base for receiving the cultures and a lid that can be placed on the base to cover it. The lid may be transparent to provide a viewing panel enabling visual examination of the cultures while the lid is in place. Culture dishes are also generally designed so that one dish can be stacked on top of another to make efficient use of laboratory resources (e.g., an incubator) shared by multiple dishes, and to facilitate transport of a number of culture dishes from one location to another.
A disadvantage of known culture dishes is that they are difficult to handle. For example, when the culture dish includes a lid, the user may have difficulty in sliding his fingers under the base to lift the dish, because the lid is wider and overlaps the base. Thus, the user may not be able to feel whether he is actually grasping the base, or just the lid. Alternatively, if a culture dish is handled with its lid removed, the cultures can become contaminated by the user's thumbs extending over the edge of the dish when grasped from the sides.
Another difficulty in handling conventional culture dishes involves lifting the dish from a surface, which requires a user to first lift an edge of the dish so that he can slide his fingers below the base. This can cause liquid growth medium to spill from the dish, even when covered with a lid. This difficulty can be compounded when a user attempts to lift a stack of multiple culture dishes.
Accordingly, it is an object of the present invention to provide an improved culture dish.